Prenatal diagnosis of fetal multicystic dysplastic kidney with two-dimensional and three-dimensional ultrasound.

Fetal multicystic dysplastic kidney (MCDK) may have grave prognosis and prenatal diagnosis of MCDK by ultrasound (US) is very important. Traditionally, MCDK is diagnosed by 2-D US. Recently, 3-D US has emerged, and may overcome the weakness of 2-D US. In this series, we retrospectively analysed the cases of MCDK diagnosed by prenatal 2-D and 3-D US from November 1995 to March 2002 to evaluate the prenatal sonographic characteristics of this disease and to compare the efficacy of 2-D and 3-D US. The 2-D assessment included the lesion of MCDK, the amniotic fluid volume and associated anomalies. The 3-D assessment included three-orthogonal multiplanar views and various rendering modes of reconstruction of MCDK. In total, 28 cases were diagnosed by prenatal 2-D and 3-D US. Within the study period, 2-D US detected 100% of MCDK, as did 3-D US, and revealed that left, right and bilateral MCDK were in 46.4%, 28.6%, and 25% of cases, respectively. Oligohydromnios was present in 6 cases (21.4%). In addition, 3-D US showed fetal MCDK vividly and provided a whole view of the disease that assisted comprehension of the severity and extent better than 2-D US. In conclusion, although 2-D US detected all the cases of fetal MCDK in utero as did 3-D US, the 3-D images generated by various rendering modes can further assist in evaluating the severity and extent of MCDK, with a novel view that substantially aids the medical team in prenatal management and the parents in genetic consultation.